400 A MCCB with ETU850 — what the ratings mean for your panel
The Siemens 3VA2340-6KP32-0JC0 is a SENTRON molded case circuit breaker rated for 400 A continuous current Iu at 40 °C through 50 °C ambient, with a 3-pole configuration and an ETU850 electronic trip unit for line protection. At 55 °C it derates to 375 A, at 60 °C to 350 A, at 65 °C to 325 A, and at 70 °C to 300 A — so if your panel runs hot, the actual ampacity drops. Breaking capacity is 242 kA at 240 V, 187 kA at 415 V and 440 V, 121 kA at 500 V, and 40 kA at 690 V, which covers most industrial distribution fault levels without cascading upstream. The ETU850 provides adjustable overload and short-circuit protection curves, plus communication and other measurement functions, making it suitable for monitored power distribution in switchgear.
Panel fit and auxiliary integration
Dimensions are 248 mm high, 138 mm wide, and 110 mm deep — a standard 3-pole MCCB footprint that fits most DIN-rail or direct-mount panel layouts. The unit ships with 2 auxiliary switches (HQ type) and a shunt trip (STL) release built in. The supplied basic switch is order code 3VA2340-6KP32-0AA0, and the integrated auxiliary trip is 3VA9688-0BL32 — both are serviceable separately if a component fails. No undervoltage release or ground-fault monitoring is included on this variant, so if you need those, this isn't the version.